Investigation of tribological properties of liquid oils with nanoparticles

In this thesis, the tribological effects of MoS2 and CaF2 additives in SAE 20W50 engine oil and boric acid additives with different morphologies in raw hazelnut oil were investigated. Experiments were carried out under different operating conditions using a block-on-ring experimental setup configured in surface contact geometry. At the end of the tests, microstructural analysis of the worn sample surfaces were examined. MoS2 and CaF2 additives showed friction and wear-reducing effects on engine oil and improved the operation of engine oil in the boundary friction region. It was concluded that alkali metal salts can be used as oil additives instead of heavy metal-containing additives. Granular and powdered boric acid additives showed reducing effects on the friction and wear behavior of raw hazelnut oil, and improved the operation of the base oil in the boundary lubrication zone. In addition, the effects boric acid morphology on lubricating properties were investigated. It was concluded that environmentally friendly and renewable boric acid added hazelnut oil can be used as an alternative lubricant to mineral based lubricants.